Because the number of active iPhone users continues to grow, indicating that more people are seeking out this integrated experience that Apple sells, rather than shun it. And the best part is - it wasn't so long ago that this exact same argument was constantly parroted as the key reason why Apple would fail, because the competition offered more "choice" for less money.
My counterpoint is - why are people so dead certain that sideloading is even something the majority of the iPhone's user base even wants, much less will benefit from, vs something that an incredibly small and vocal group of users here on Macrumours want to foist on everybody just for their own selfish desires?
There seems to be this growing narrative that Apple users are stuck or imprisoned in a massive walled garden, held captive by their Apple Watches and iMessage and AirPods. That only the government can protect us from Apple and they we are all just waiting for regulators to swoop down and smash open the walled garden and free us all.
People who buy an iPhone go on to buy an iPhone again and again and again. Apple is also attracting more android switchers to their platform, resulting in net growth of active users every year, so clearly they must be doing something right if they are able to lure users away despite lacking the very features and functionality that make Android uniquely android.
The way I see it, the people who believe this narrative are just setting themselves up for failure. For some inexplicable reason, I have observed that there is this group of people here who just want Apple to fail, and in the process, they have latched on to every single trend in technology and argued that it's the next big thing (the implication is that Apple is lagging behind by not hopping on obviously hare-brained schemes).
Arguing that Apple users are somehow being forced against their will to buy products like Apple Watches and AirPods is nothing more than looking for someone to blame for market failures when the problem is (more often than not) due to the competition possessing bad vision, inadequate corporate culture, and an overall lack of understanding as to what makes Apple unique.
And by parroting the same arguments made by these companies, these people are all just demonstrating that same lack of understanding about what makes Apple tick, or how Apple has been able to use their unique strengths to stand out from the competition. These recent antitrust headlines have made for juicy headlines capable of grabbing people’s attention, no doubt, but I am confident they won’t play a major role in Apple’s future. Apple is where it is today by saying “no” more than “yes", by remaining focused on making technology more personal, and by sticking with a design-led culture to push the user experience.
Through this, Apple is able to develop a dynamic, yet nimble, ecosystem of tools that people are willing to pay for. As such, I am reasonably optimistic that Apple will be able to wade through all these antitrust challenges (but present and future) and emerge relatively unscathed. I know it may not seem that way now with the DMA, but I have hope.